This invention relates generally to gas ovens and more particularly to control and ignition systems for gas ovens.
Household gas ovens typically include at least a broil burner, typically positioned towards the top of an oven chamber, and a bake burner, typically positioned towards the bottom of the oven chamber. Conventional ignition systems for gas ovens typically include a hot surface ignitor, for example a glowbar, in conjunction with a thermally operated gas control valve. The thermally operated gas control valve opens so as to permit gas flow to the respective burner assembly only when a specified current has been established through the glowbar. The specified current corresponds to a glowbar temperature that will ignite the gas flow upon introduction.
Accordingly, a system user selects the type of gas oven operation needed, for example bake mode or broil mode, typically by manipulating a control knob. Once selected, the glowbar begins heating and the current increases until it reaches a steady state. After the current rises above the lower limit for ignition, the thermally operated gas control valve opens, the fuel is ignited, and a flame is established at the selected burner.
One current problem with the beforementioned ignition systems is cost. In the highly competitive household gas oven market, any unnecessary or excessive costs should be avoided. In the beforementioned ignition system both the thermostatic gas control valves and the hot surface ignitors are expensive components for a household gas oven system, and the hot surface ignitors are subject to frequent breakage. Additionally, misalignment of the hot surface ignitor relative to the thermostatic gas valve may delay or prevent burner ignition.
Another current problem with commercially available gas ovens is that once gas is issued through a burner element and an ignition attempt is made, there is no mechanism for ensuring the ignition attempt was successful. Additionally, even if the ignition attempt was successful, there is no mechanism for determining if there is a flameout at the burner element.
Therefore, it is apparent from the above that there exists a need in the art for improvements in safe, low cost gas oven ignition and detection systems.